This invention relates to a control system for controlling a number of functions on an agricltural implement, such as a forage harvester or the like, from an operator's station on the tractor.
Farm implements, such as forage harvesters, conventionally have a nuumber of components or functions that are adjusted during the operation and transport of the machine. Such functions as the header lift system have been controlled by hydraulic cylinders controlled from the tractor, hydraulic outlets or coupling elements being provided on the rear of the tractor for connection to hydraulic lines on the implement via disconnectible couplers, the supply and exhaust from the outlets being controlled by control levers at the operator's station on the tractor. However, adjustable functions on the forage harvester, such as the position of the discharge spout deflector cap, the rotational position of the discharge spout, or the condition of the feed roll transmission have required less power, and have been manually controlled by control linkages or rods extending forwardly from the implement to the tractor operator station for manual control by the operator from the tractor seat.
However, in more recent years, an increasing number of tractors have been provided with fully enclosed cabs, the majority of newer tractors used for field work being provided with cabs that are not only fully closed, but sealed and pressurized to prevent the entry of dust, sound-proofed, heated, and air conditioned. Of course, it is impossible to manipulate control rods or linkages from a tractor seat from a fully enclosed operator station, and it is therefore known to provide electro-hydraulic control systems for controlling the low power adjustable functions on the implement, the electro-hydraulic systems including switches at the operator's station and electric lines leading to electro-hydraulic devices on the implement. Newer tractors are conventionally provided with up to three pairs of hydraulic outlets at the rear of the tractor for controlling up to three remote hydraulic cylinders, so that in some cases it is possible to control two additional functions on the implement in addition to the header lift system. However, in some cases, the tractor may only be equipped with one or two sets of outlets, and it is therefore not possible to utilize the tractor hydraulic system for remotely controlling all of the hydraulic functions on the implement.